IB Physics SL C 3 3 Refractive Index Topic Practice

A group of students is investigating refraction in a semi-circular glass block.

Light from a ray box enters the curved side of the block. The light passes through the block and leaves, refracted, at P .

They plot a graph of the variation with the sine of $\theta_{i}$ of the sine of $\theta_{r}$.
They add uncertainty bars for $\sin \theta_{r}$ for the first and last data point and draw the best-fit line.

Determine the value of the refractive index of the glass with its absolute uncertainty.